/****************************************************************************
 *
 * Copyright 2016 Samsung Electronics All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific
 * language governing permissions and limitations under the License.
 *
 ****************************************************************************/
/***********************************************************************
 * example/kernel_sample/sem.c
 *
 *   Copyright (C) 2007-2009 Gregory Nutt. All rights reserved.
 *   Author: Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ***********************************************************************/

/***********************************************************************
 * Included Files
 ***********************************************************************/

#include <stdio.h>
#include <pthread.h>
#include <semaphore.h>
#include <sched.h>
#include "kernel_sample.h"

/***********************************************************************
 * Pre-processor Definitions
 ***********************************************************************/

#ifndef NULL
# define NULL (void*)0
#endif

/***********************************************************************
 * Private Data
 ***********************************************************************/

static sem_t sem;

/***********************************************************************
 * Private Functions
 ***********************************************************************/

static void *waiter_func(void *parameter)
{
	int id = (int)parameter;
	int status;
	int value;

	printf("waiter_func: Thread %d Started\n",  id);

	/* Take the semaphore */

	status = sem_getvalue(&sem, &value);
	if (status < 0) {
		printf("waiter_func: ERROR thread %d could not get semaphore value\n",  id);
	} else {
		printf("waiter_func: Thread %d initial semaphore value = %d\n",  id, value);
	}

	printf("waiter_func: Thread %d waiting on semaphore\n",  id);
	status = sem_wait(&sem);
	if (status != 0) {
		printf("waiter_func: ERROR thread %d sem_wait failed\n",  id);
	}
	printf("waiter_func: Thread %d awakened\n",  id);

	status = sem_getvalue(&sem, &value);
	if (status < 0) {
		printf("waiter_func: ERROR thread %d could not get semaphore value\n",  id);
	} else {
		printf("waiter_func: Thread %d new semaphore value = %d\n",  id, value);
	}

	printf("waiter_func: Thread %d done\n",  id);
	return NULL;
}

static void *poster_func(void *parameter)
{
	int id = (int)parameter;
	int status;
	int value;

	printf("poster_func: Thread %d started\n",  id);

	/* Take the semaphore */

	do {
		status = sem_getvalue(&sem, &value);
		if (status < 0) {
			printf("poster_func: ERROR thread %d could not get semaphore value\n",  id);
		} else {
			printf("poster_func: Thread %d semaphore value = %d\n",  id, value);
		}

		if (value < 0) {
			printf("poster_func: Thread %d posting semaphore\n",  id);
			status = sem_post(&sem);
			if (status != 0) {
				printf("poster_func: ERROR thread %d sem_wait failed\n",  id);
			}

			pthread_yield();

			status = sem_getvalue(&sem, &value);
			if (status < 0) {
				printf("poster_func: ERROR thread %d could not get semaphore value\n",  id);
			} else {
				printf("poster_func: Thread %d new semaphore value = %d\n",  id, value);
			}
		}
	} while (value < 0);

	printf("poster_func: Thread %d done\n",  id);
	return NULL;

}

/***********************************************************************
 * Public Functions
 ***********************************************************************/

void sem_test(void)
{
	pthread_t waiter_thread1 = (pthread_t)0;
	pthread_t waiter_thread2 = (pthread_t)0;
	pthread_t poster_thread = (pthread_t)0;
#ifdef SDCC
	pthread_addr_t result;
#endif
	struct sched_param sparam;
	int prio_min;
	int prio_max;
	int prio_mid;
	pthread_attr_t attr;
	int status;

	printf("sem_test: Initializing semaphore to 0\n");
	sem_init(&sem, 0, 0);

	/* Start two waiter thread instances */

	printf("sem_test: Starting waiter thread 1\n");
	status = pthread_attr_init(&attr);
	if (status != OK) {
		printf("sem_test: pthread_attr_init failed, status=%d\n",  status);
	}

	prio_min = sched_get_priority_min(SCHED_FIFO);
	prio_max = sched_get_priority_max(SCHED_FIFO);
	prio_mid = (prio_min + prio_max) / 2;

	sparam.sched_priority = (prio_mid + prio_max) / 2;
	status = pthread_attr_setschedparam(&attr, &sparam);
	if (status != OK) {
		printf("sem_test: ERROR: pthread_attr_setschedparam failed, status=%d\n",  status);
	} else {
		printf("sem_test: Set thread 1 priority to %d\n",  sparam.sched_priority);
	}

	status = pthread_create(&waiter_thread1, &attr, waiter_func, (pthread_addr_t)1);
	if (status != 0) {
		printf("sem_test: ERROR: Thread 1 creation failed: %d\n",  status);
	}

	printf("sem_test: Starting waiter thread 2\n");
	status = pthread_attr_init(&attr);
	if (status != 0) {
		printf("sem_test: ERROR: pthread_attr_init failed, status=%d\n",  status);
	}

	sparam.sched_priority = prio_mid;
	status = pthread_attr_setschedparam(&attr, &sparam);
	if (status != OK) {
		printf("sem_test: ERROR: pthread_attr_setschedparam failed, status=%d\n",  status);
	} else {
		printf("sem_test: Set thread 2 priority to %d\n",  sparam.sched_priority);
	}

	status = pthread_create(&waiter_thread2, &attr, waiter_func, (pthread_addr_t)2);
	if (status != 0) {
		printf("sem_test: ERROR: Thread 2 creation failed: %d\n",  status);
	}

	printf("sem_test: Starting poster thread 3\n");
	status = pthread_attr_init(&attr);
	if (status != 0) {
		printf("sem_test: ERROR: pthread_attr_init failed, status=%d\n",  status);
	}

	sparam.sched_priority = (prio_min + prio_mid) / 2;
	status = pthread_attr_setschedparam(&attr, &sparam);
	if (status != OK) {
		printf("sem_test: pthread_attr_setschedparam failed, status=%d\n",  status);
	} else {
		printf("sem_test: Set thread 3 priority to %d\n",  sparam.sched_priority);
	}

	status = pthread_create(&poster_thread, &attr, poster_func, (pthread_addr_t)3);
	if (status != 0) {
		printf("sem_test: ERROR: Thread 3 creation failed: %d\n",  status);
		printf("          Canceling waiter threads\n");

		pthread_cancel(waiter_thread1);
		pthread_cancel(waiter_thread2);
	}

#ifdef SDCC
	if (waiter_thread1 != (pthread_t)0) {
		pthread_join(waiter_thread1, &result);
	}

	if (waiter_thread2 != (pthread_t)0) {
		pthread_join(waiter_thread2, &result);
	}

	if (poster_thread != (pthread_t)0) {
		pthread_join(poster_thread, &result);
	}
#else
	if (waiter_thread1 != (pthread_t)0) {
		pthread_join(waiter_thread1, NULL);
	}

	if (waiter_thread2 != (pthread_t)0) {
		pthread_join(waiter_thread2, NULL);
	}

	if (poster_thread != (pthread_t)0) {
		pthread_join(poster_thread, NULL);
	}
#endif
	sem_destroy(&sem);
}
